Many organizations have discovered that the cost, effort, and risk required to replace older legacy systems with modern software and database systems are overwhelming. Rather, organizations continue to place an emphasis on supporting legacy systems by bridging gaps between old and new computing technologies, wherein bridging the gap often includes modification of existing legacy data and programming languages.
COBOL is one such programming language. Despite the existence of modern, object-oriented programming languages and Internet-based applications, COBOL will likely remain a vital part of many organizations' computing centers. Traditional COBOL, however, lacks some of the flexibility of modern languages, such as the ability to read extensible markup language (XML) documents.
XML resembles Hypertext Markup Language (HTML) in appearance and structure; however, XML is functionally different: HTML specifies how to display data, while XML is used to describe data. Accordingly, XML has provided developers with a means for displaying different types of data in a consistent manner. Generally, a developer may create formatting instructions within a data type definition (DTD) file. When a data type is defined, a developer need only add an XML tag within an HTML document which corresponds to a tag in the DTD.
Because COBOL is a legacy programming language, it must often be retrofitted to support various functionality relating to newer computing technologies. Technologies such as XML were not designed with older computing technologies such as COBOL in mind. Modifying the language or creating add-on products most often results in extra layers of sophistication and complexity for the developer. One such example is “XML PARSE,” which is a function included within IBM® Enterprise COBOL. While XML PARSE provides an effective means to parse and process various types of XML, it may still present a formidable task for developers in that they must be aware of all of the events associated with the verb. Further, it typically requires the creation of complex COBOL structures that mimic XML data structures.